An HST dataset is "released" when its proprietary period expires.
The default proprietary period of HST data is one year from the time of ingest into MAST,
though some observing programs or datasets may have been granted shorter or longer proprietary periods.
Once the dataset is released, it may be retrieved from MAST without special authorization.
Principal investigators and co-investigators may have their MAST archive accounts enabled
to retrieve proprietary data from their observing programs.
Contact archive@stsci.edu for more information.

The links labelled gz are the gzip-compressed versions of the reports.
Most modern browsers are capable of handling compressed HTML on the fly,
so these compressed versions may download significantly faster for you
than the uncompressed versions, especially over a slow Internet connection.